Rotor for a threshing system of an agricultural combine and method of making the same

Abstract

A rotor for a threshing system of an agricultural combine and method for making the same, including a body of simplified, three part press fit construction including an inlet segment, a main body segment having threshing elements therearound, and a bulkhead to be connected to a drive mechanism. The inlet segment, main body segment and bulkhead are configured so as to facilitate press fit assembly thereof concentric about a rotational axis about which the rotor will be rotated during operation, while also minimizing eccentricities of those components. As a result, the manufacture of the rotor is simplified by the elimination of the need for an internal skeleton structure and associated welds and/or fasteners.

1. A method of making a rotor for a threshing system of an agricultural combine, comprising steps of:
 providing an inlet segment having a rigid lip centered about a rotational axis, the lip having a predetermined shape and an axially tapered peripheral surface having a first predetermined transverse dimension measured through the rotational axis; 
 providing a tubular main body segment having a first open end portion and a second open end portion, the first open end portion being configured and sized to be press fit to the tapered peripheral surface of the lip of the inlet segment concentric about the rotational axis, and the first open end portion of the tubular main body segment being configured and sufficiently compliant so as to be conformable to the predetermined shape and transverse dimension of the lip when press fit thereto; 
 providing a disk shaped bulkhead including a center hub having a central axis therethrough and an outer skirt extending around the hub and centered about the axis therethrough, the outer skirt being configured to be press fit to the second open end portion of the main body segment; and 
 assembling the inlet segment, the main body segment, and the bulkhead together, by press fitting the first open end portion of the main body segment onto the lip of the inlet segment so as to conform thereto, and by press fitting the skirt of the bulkhead to the second open end portion of the main body segment, such that the bulkhead, the main body segment and the inlet segment are concentric about the rotational axis. 
 
     
     
       2. The method of  claim 1 , wherein in the step of assembling, the skirt of the bulkhead is press fit to the second open end of the main body segment using an axially directed force of several thousand pounds. 
     
     
       3. The method of  claim 1 , wherein the skirt has a peripheral surface having a tapered shape configured for cooperatively engaging the second open end portion of the main body segment when the skirt is press fit thereto. 
     
     
       4. The method of  claim 3 , wherein in the step of assembling, the skirt of the bulkhead is press fit to the second open end portion of the main body segment in predetermined axial relation to the inlet segment for establishing an axial length dimension of the rotor. 
     
     
       5. The method of  claim 3 , wherein the skirt of the bulkhead is radially deformable so as to conform to a shape of the second open end portion of the main body segment when press fit thereto. 
     
     
       6. The method of  claim 3 , wherein the peripheral surface of the skirt is radially outwardly facing and is cooperatively receivable in the second open end portion of the main body segment. 
     
     
       7. The method of  claim 1 , comprising a step of providing an apparatus configured for holding the inlet segment, the main body segment, and the bulkhead concentric about the rotational axis, and wherein the step of assembling includes using the apparatus for press fitting the inlet segment, the main body segment, and the bulkhead together. 
     
     
       8. The method of  claim 1 , comprising a step of cutting the skirt of the bulkhead after being press fit to the second open end portion of the main body segment, for establishing an overall axial length of the rotor. 
     
     
       9. The method of  claim 1 , wherein the axially tapered peripheral surface of the lip is radially outwardly facing and is cooperatively receivable in the first open end portion of the main body segment. 
     
     
       10. A rotor for a threshing system of an agricultural combine, made by a process comprising steps of:
 providing an inlet segment having a rigid lip centered about a rotational axis, the lip having a predetermined shape and an axially tapered peripheral surface having a first predetermined transverse dimension measured through the rotational axis; 
 providing a tubular main body segment having a first open end portion and a second open end portion, the first open end portion being configured and sized to be press fit to the tapered peripheral surface of the lip of the inlet segment for securely joining the inlet segment and the main body segment together concentric about the rotational axis, and the first open end portion of the tubular main body segment being configured and sufficiently compliant so as to be conformable to the predetermined shape and transverse dimension of the lip when press fit thereto; 
 providing a disk shaped bulkhead including a center hub having a central axis therethrough and an outer skirt extending around the hub and centered about the axis therethrough, the outer skirt being configured to be press fit to the second open end portion of the main body segment; and 
 assembling the inlet segment, the main body segment, and the bulkhead together, by press fitting the first open end portion of the main body segment onto the lip of the inlet segment so as to conform thereto, and by press fitting the skirt of the bulkhead to the second open end portion of the main body segment, such that the bulkhead, the main body segment and the inlet segment are concentric about the rotational axis. 
 
     
     
       11. The rotor of  claim 10 , wherein in the step of assembling, the skirt of the bulkhead is press fit to the second open end of the main body segment using an axially directed force of several thousand pounds. 
     
     
       12. The rotor of  claim 10 , wherein the skirt has a peripheral surface having a tapered shape configured for cooperatively engaging the second open end portion of the main body segment when the skirt is press fit thereto. 
     
     
       13. The rotor of  claim 12 , wherein the peripheral surface of the skirt is radially outwardly facing and is cooperatively receivable in the second open end portion of the main body segment. 
     
     
       14. The rotor of  claim 10 , wherein in the step of assembling, the skirt of the bulkhead is press fit to the second open end portion of the main body segment in predetermined axial relation to the inlet segment for establishing an axial length dimension of the rotor. 
     
     
       15. The rotor of  claim 10 , wherein the skirt of the bulkhead is radially deformable so as to conform to a shape of the second open end portion of the main body segment when press fit thereto. 
     
     
       16. The rotor of  claim 10 , wherein the process additionally comprises a step of providing a fixture configured for holding the inlet segment, the main body segment, and the bulkhead concentric about the rotational axis, and wherein the step of assembling includes using the fixture for press fitting the inlet segment, the main body segment, and the bulkhead together. 
     
     
       17. The rotor of  claim 10 , comprising a step of cutting the skirt of the bulkhead after being press fit to the second open end portion of the main body segment, for establishing an overall axial length of the rotor. 
     
     
       18. The rotor of  claim 10 , wherein the axially tapered peripheral surface of the lip is radially outwardly facing and is cooperatively receivable in the first open end portion of the main body segment. 
     
     
       19. A method of making a rotor for a threshing system of an agricultural combine, comprising steps of:
 providing an inlet segment having a frusto-conical portion extending in one direction and a circumferential lip extending in an opposite second direction, the frusto-conical portion and the lip being concentric about a rotational axis extending in the first and second directions, the lip including a tapered outer circumferential surface portion having a predetermined diametrical extent; 
 providing a tubular main body segment having a first open end portion and a second open end portion, at least the first open end portion including an inner circumferential surface therearound having a diametrical extent about equal to the predetermined diametrical extent of the tapered outer circumferential surface portion; 
 providing a disk shaped bulkhead including an outer skirt extending therearound, the outer skirt having an outer circumferential surface portion having a predetermined diametrical extent marginally larger than an inner diametrical extent of the second open end portion, the outer skirt being compressible radially inwardly substantially uniformly therearound; 
 assembling the inlet segment and the main body segment by press fitting the lip of the inlet segment into the first open end of the main body segment such that the inner circumferential surface is conformingly engaged with the tapered outer circumferential surface for holding the tubular main body segment substantially concentric with the frusto-conical portion and the lip; and 
 assembling the main body segment and the bulkhead by press fitting the bulkhead into the second open end of the main body segment such that the outer skirt is radially compressed thereby for holding the bulkhead substantially concentric with the tubular body segment, the frusto-conical portion, and the lip. 
 
     
     
       20. The method of  claim 19 , wherein the outer circumferential surface of the outer skirt has a tapered shape. 
     
     
       21. The method of  claim 19 , wherein the predetermined diametrical extent of the outer circumferential surface of the skirt is about equal to the predetermined diametrical extent of the tapered outer circumferential surface portion of the lip. 
     
     
       22. The method of  claim 19 , wherein the process comprises another step of providing an apparatus for assembling the main body segment and the bulkhead, the apparatus being capable of holding the bulkhead concentric with the inlet segment as the bulkhead is inserted into the second open end of the main body segment. 
     
     
       23. The method of  claim 19 , wherein the process comprises an additional step of trimming the skirt of the bulkhead to set an overall axial length of the rotor.